The NIa protease of Turnip mosaic virus improves growth and reproduction of its aphid vector, Myzus persicae (green peach aphid)

Many plant pathogens depend on phloem feeding insects, such as aphids, for transmission within and among host plants. Thus, aphid feeding and behavior can affect the rate of pathogen transmission. In response to this, many viruses manipulate plant-aphid interactions to promote their own transmission, although the molecular mechanisms controlling these interactions remain unclear. In the present study, Myzus persicae (green peach aphid) fecundity was elevated on host plants infected with Turnip Mosaic Virus (TuMV) compared to aphids feeding on uninfected controls. Further experiments revealed that TuMV infection suppresses gene expression related to aphid-specific plant defenses and increases free amino acids available for insect nutrition. The involvement of specific TuMV proteins in aphid success on virus-infected plants was investigated. These data reveal expression of at least one viral protein contributes to increased aphid success and that the relationship may benefit not only the pathogen that is transported from plant to plant but also its insect host.